You can't go to Route 11 unless you first defeat the Pokemon League in Pokemon Black.
You have to beat the elite four. Then beat Ghetsis and N.
Route 11 only opens when you beat the main story line.
Above route 11.
Route 11, Village Bridge (Black only)
Go to Route 1 and surf over to Route 18.
Go to Route 5 after you defeat Elesa in Pokemon Black Version.
Route 6, 11 (All), Route 8, Icirrus City, Moor of Iccirus (Spring, Summer, Autumn)
You can't find Audino in Pokemon Diamond. You can only find it in Pokemon Black and/or White (Well so far you can only catch it in them)! To catch Audino in Pokemon Black/White, you have to go to either: route 18, route 1, P2 Laboratory, route 2, Dreamyard, route 3, Pinwheel forest, route 5, route 6, Cold Storage, route 7, Dragonspiral Tower, route 9, route 10, route 11, Village bridge, route 12, Giant Chasm, Route 13, route 14, Abundant Shrine, route 15, route 16 or Lostlorn Forest.
go to route 18
go to the day care on route 3
Go past the house on route 5.
go to route 20